1. Field of the Invention
The invention relates to a sheet guide for a small printer.
2. Description of the Related Art
As shown in FIGS. 11 and 12, conventional sheet guide mechanisms are characterized as fixing a record sheet inserting section and a sheet guide passage forming member contiguous thereto on the frame of a printer in order to provide a gap for the passage of the record sheet. An example shown in FIG. 11 is designed to fix a sheet guide (inner) 125 and a sheet guide (outer) 126 by engaging their mounting sections 125a, 125b, 126a and 126b with frames 120, 121 of the printer with caulking or the like. An example shown in FIG. 12 is constructed so that the frame 131 itself serves as a sheet guide (outer) component. A sheet guide (inner) 135 is fixed on the frame 131 with sheet guide holding screws 138. Therefore, the gap for the passage of a record sheet is invariable in the conventional examples.
These conventional examples reveal the following problems. Since the record sheet inserting inlet and the sheet guide passage forming member are either fixed on the frame, etc. or part of the frame itself, an attempt to increase the opening of the inserting inlet for a better insertion of the record sheet leaves a large gap at all times. This causes jamming at the sheet guide passage because such large gap allows sheets and foreign matter to enter therefrom.
In the case of a rolled record sheet such as a pressure-sensitive copying sheet, printing is done by inserting a plurality of rolled sheets with their ends flush. Since the inner diameter of the roll is different from the outer diameter by the thickness of the sheet, the inner record sheet is shorter than the outer record sheet. As a result, even if neither sheet is slack at the time of insertion, the record sheets other than the innermost one become gradually loose between the record sheet inserting inlet of the printer and the roll, because it is the innermost record sheet having the shortest circumference that pulls and rotates the roll to unwind the roll of record sheets. The slack of the record sheets becomes easier to be threaded into the record sheet inserting inlet while tucked and folded as the opening of the record sheet inserting inlet becomes wider. Once the record sheets have been threaded while folded, their thickness doubles, thereby causing the record sheets to jam along the sheet guide passage.
In the case of such jamming of sheets and clogging of foreign matter, the record sheets or foreign matter blocking the sheet guide passage must be eliminated to restore normal passage of sheets. The conventional structure in which the record sheet inserting inlet and the sheet guide passage forming member are fixed on the frame or the like is disadvantageous in eliminating such record sheets or foreign matter once the record sheets or foreign matter have been caught in the depth of the narrow and bent sheet guide passage.